Electric switch



March 9, 1937. R. F. SAMBLESON ELECTRIC SWITCH Filed Nov. 15, 1955 Inventor. Robert F Sambleson, b9 E. l-hs ctor-ney.

Patented Mar. 9, 1937 UNTED STATES "PATENT GFFICE ELECTRIC SWITCH Robert F. Sambleson, Bridgeport, Comm, assignor to General Electric lDompany, a corporation or New York The present invention relates to double-pole electric switches of the type having a liquid contact circuit closer for controlling one side of a two wire circuit and mechanical contacts for controlling the other side of the two wire circuit.

The object of my invention is to provide an improved construction and arrangement in a switch of this type, and for a consideration of what I believe to be novel and my invention, attention is p directed to the accompanying description and the claims appended thereto.

In the accompanying drawing, Fig. 1 is a plan view partly broken away of a switch embodying my invention; Fig. 2 is a perspective view partly 3 in section; Fig. 3 is a diagrammatic view showing the construction and operation of the liquid contact circuit closer; and Fig. 4 is a sectional View taken on line 4 -4 of Fig. 1.

Referring to the drawing, I have illustrated my invention using a liquid contact circuit closer having a pair of cup-shaped metal terminals 5 which are separated by an insulating diaphragm 2 of refractory material, such as a ceramic. The edges of the terminals are sealed by a bead 3 of glass which also seals the junctions between the .diaphragm and the terminals. Within the space enclosed by the terminals is a suitable quantity of mercury 4 which forms the conducting medium between the terminals. In the manufacture of the switch, the space enclosedby the terminals is evacuated and filled with hydrogen at a pressure of one or more atmospheres which increases the current interrupting capacity of the circuit closer. As shown in Fig. 3, thediaphragm 2 55 is provided with an opening 5 which is submerged in the mercury when the circuit closer is in the current conducting position, as shown by the dotted lines in Fig. 3. When the circuit closer is in the current interrupting position shown in 40 full lines in Fig. 3, the opening 5 is above the mercury, and the circuit between the terminals is therefore interrupted by the insulating diaphragm 2. Due to the construction of the circuit closer, the interruption of the circuit be- 5 tween the terminals takes place in the mercury as the circuit closer is turned so that the opening 5 in the diaphragm approaches the full line position. The above-described construction is illustrative of a liquid contact circuit closer which 5 is suitable for use in a. switch embodying my invention.

' The circuit closer is mounted within a housing 6 having side walls la. and lb and a central partition 8. Between the side wall la and the par- 55 tition 8 isa pair of contacts 9, which, as shown in Fig. 4, are secured to bosses it on the housing by the spun-over portions i ll of inserts l2 molded in the bosses. Terminal screws l3 are threaded into the inserts l2 and provide a means for clamping the line conductors of one side of a two Wire 5 circuit to the contacts 9. The bottomedges of the contacts 9 rest on shoulders it formed respectively on the partition 8 and the side wall la. Theportions of the contacts 9 adjacent the terminals l of the circuit closer are provided with 10 circular projections 55 which fit into complementary recesses l6 in the terminals. The projections l5 and the depressions I6 provide ball and socket connections which support the circuit closer and permit it to rotate about its axis. The wiping action between the terminals and the contacts tends to prevent increase of contact resistance. The contacts 9 are prevented from spreading by the ,side wall la and the partition 8 so that the liquid contact circuit closer is securely held between the contacts.

Between the partition 8 and the side Wall lb are spring strips I! which are secured at one end to bosses it on the housing in the same manner that the contacts 9 are secured to the bosses ID. 5 Terminal screws l9 are threaded into the inserts l2 which secure the spring strips I! to the housing and form the terminals for the other side of the two wire circuit of the switch. On the inner ends of the spring strips H are contacts 20 o which are normally biased together by the resilience of the spring strips.

For operating the switch, I have provided a handle 2| having a curved flange 22 at its lower end which rests on the curved surface 23 of the partition 8 and also having a curved flange 24 on the other side of the handle which fits over the terminal of the circuit closer adjacent the partition 8.. The surface 24 of the handle is provided with a projection 25 which fits into a complementary recess 26 in the terminal and prevents relative rotation between the circuit closer and the'handle. The curved surface 23 provides a bearing on which the handle turns. The handle is held in place by spring strips 2'l which engage projections 28 formed on each of the flanges 22 and 24. The portions of the spring strips 21 which engage the projectionsZB are relatively fiat compared to the curved flanges 22 and 24 of the handle so that it is apparent that 5 the springs tend to bias the handle to either side of the central position. At either end the spring I strips 21 are bent to provide resilient stops 29 which engage the sides of projections 28 and limit the movement of the handle ill. The stops 29 are resilient and therefore decrease the noise resulting from the impact of the projections 28 with the stops. The spring strips 21 are riveted to a mounting strap 30- which is secured to the housing by screws 3| extending through the housing from the bottom. The mounting strap is used for mounting the switch in an outlet box and, when so mounted, the right-hand end of the mounting strap should be at the top. A dust cover 32 encloses the upper 'side of the housing.

The flange 22 of the handle is provided with a depending rod 33 of insulating material which, as shown in Figs. 2 and 3, is adapted to engage the lower spring strip I1 and separate the contacts 20 when the handle 2| is moved to the upper position.

In the assembly of the switch, the spring strips II are secured to the bosses l8 by the spun-over portions ll of the inserts I2, and the terminal screws l9 are threaded into the inserts. The contacts 9 are then assembled on'each side of the liquid contact circuit closer so that the projections I5 fit within the depressions H5 in the terminals. Before assembly, the ends of the contacts 9 may be bent inwardly so as to increase the contact pressure on the terminals. The contacts and the liquid contact circuit closer are then inserted into the housing, and the ends of the contacts 9 are secured to the bosses ID by the spun-over portions ll of inserts l2. The circuit closer is now securely held in the housing and is supported for rotation about its axis. Terminal screws l3 are then threaded into the inserts 2. The handle 2| is then placed on the housing so that the flange 22 engages the curved surface 23, and the projection 25 fits within the depression 26 in the terminal l adjacent the partition 8. The dust cover 32 placed over the housing and the mounting strap dropped over the handle and secured to the housing by screws 3|, thereby holding the dust cover on the topof the housing. When themounting strap is secured in place, the springs 21 exerta downward force on the handle which holds the handle on the circuit closer and the curved surface 23 and also exerts a downward force on the circuit closer which increases the contact pressure between the contacts 9 and the terminals 4 In the use of the switch, the switch is mounted in an outlet box so that the right-hand end of the mounting strap 30 is at the top of the box. The y terminals |3 are then connected in one side of a two-wire circuit, and the terminals l9 are connected in the other side of a two-wire circuit. The operation of the switch is diagrammatically shown in Fig. 3. From this figure, it is apparent that as the handle 2| is raised, the liquid contact circuit closer will be moved to a posi- I tion in which the opening 5 in the diaphragm 3. is above the mercury in the circuit closer,- and the circuit between-the terminals of the liquid contact circuit closer is therefore broken. Since the terminals of the liquid contact circuit closer are connected in one side of a two wire circuit, the opening of the liquid contact circuit closer interrupts the current which was flowing in the two wire circuit. Continued raising of the handle 2| causes the rod 33 to engage the lower spring strip "and thereby separate the contacts 20, thus opening theother side of the circuit. As the circuit has been broken by the opening of the liquid contact circuit closer, no current is flowing when the contacts 20 are separated. Upon lowering of the handle 2|, the rod 33 will first be moved away from the lower spring strip and the contacts 20 will be closed Since this closes only one side of the two Wil'l circuit, no current flows upon closing of thl contacts 20. Continued downward movement 0: the handle 2| causes the opening 5 in the diaphragm 2 of the circuit closer to be submerge: in the mercury, thereby completing the circui between the terminals of the circuit closer anc closing the other side of the two wire circuit As soon as the circuit is closed by the circuil closer, current may flow in the two wire circuit It is therefore apparent that although only 2 single liquid contact circuit closer is used in this switch, the making and breaking of the two wire circuit is completed through the liquid contact circuit closer.

It is apparent that by difierent positioning oi the hole 5 in the diaphragm and the contacts I1. the circuit controlled by the switch may be closed with the handle in the raised position and also the switch may be mounted in other than vertical positions.

No claim is made in this application to the arrangement of the contact strips 9 in the housing, the supporting of the circuit closer on the projections 5 on the contact strips,.or the arrangement for holding the handle 2| on the circuit closer and connecting it -thereto, these features being claimed in my applications S. N. 49,928 and 49,930, both filed Nov. 15, 1935.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In combination, a liquid contact circuit closer having opposd cup-shaped terminals, means for supporting the circuit closer for rotation about the axis of its terminals, a switch including separable contacts, a partition between said switch and said circuit closer having an arcuate surface concentric with the adjacent terminal of the circuit closer, a handle bearing on said arcuate surface and said adjacent terminal, said handle and terminal having interfitting portions for preventing relative rotation therebetween, and an operating connection between said handle and said switch. 2. In combination, a liquid contact circuit closer having opposed cup-shaped terminals, means for supporting the circuit closer for rotation about the axis of its terminals, a switch including a contact {carried by a spring strip, a partition between said switch and said circuit closer having an arcuate surface concentric with the adjacent terminal of the circuit closer, a handle bearing on said' arcuate surface and said adjacent terminal, said handle and terminal having interfitting portions for preventing relative rotation therebetween, and a projection on said handle engaging said spring strip 'for operating said switch.

n 3. In combination, a liquid contact circuit ;for preventing relative rotation therebetween,

and a projection on said handle engaging said spring strip for operating said switch.

4. In combination, a liquid contact circuit closer having opposed cup-shaped terminals, means for supporting the circuit closer for rotation about the axis of its terminals, a switch including separable contacts, a partition between said switch and said circuit closer having an arcuate surface concentric with the adjacent terminal of the circuit closer, a handle bearing on said arcuate surface, said handle having a connection with said circuit closer for rotating the circuit closer, and an operating connection between said handle and said switch.

5. In combination, a liquid contact circuit closer, means for supporting the circuit closer for rotation about an axis, a switch including separable contacts, a partition between said switch and said circuit closer having an arcuate surface concentric with said axis, a handle bearing on said'arcuate surface, an operating connection between said handle and said circuit closer, and an operating connection between said handle and said switch.

ROBERT F. SAMBLESON. 

